Neanderthal Fossil Indicates Incest Was Common

Researchers examining the DNA extracted from the fossilized toe of a 50,000-year-old Siberian Neanderthal woman believe that the woman was the child of an incestuous relationship.

The scientific journal Nature, which published the findings, also asserted that incest among Neanderthals was not taboo. The toe bone, found in 2010, yielded to scientists the woman’s genome, and that information was then processed through a number of simulated inbreeding scenarios. The scientists ascertained that the woman’s parents were either half-siblings born from the same mother or double first cousins. It also was theorized that the woman’s parents could have come from different generations of the same extended family.

University of California at Berkley population geneticist Montgomery Slatkin, a researcher on the project, said that the possible parental combinations could include an aunt/nephew, uncle/niece, grandfather/granddaughter, or grandmother/grandson.

Deputy Director of the University of Adelaide’s Australian Centre for Ancient DNA Jeremy Austin said the period in which the Neanderthal woman lived was an era during which the Neanderthals were going extinct. Consequently, there were fewer choices for breeding. He stated, “On that basis, it’s not particularly surprising. You can imagine they would have been living in very small and isolated family groups.”

The team of researchers was led by scientists from Germany’s Max Planck Institute of Evolutionary Anthropology. They found that the genome sequence of the woman showed low levels of genetic diversity, indicating a small, sedentary population. The researchers also found that the genome sequence hinted that Neanderthals interbred with the Denisovans and that another human ancestor may have been part of the pattern, possibly Homo erectus.

Austin was more interested in the possibility of interbreeding between Neanderthals and Denisovans than inbreeding among only Neanderthals. He said, “This new DNA sequence from this toe bone suggests that Denisovans and Neanderthals were also interbreeding.”

There has already been evidence of interbreeding between Neanderthals and modern humans, as well as between Denisovans and modern humans.